Torque Limiting Bolt Shearable Shaft Insulated Plug
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Solution Overview
Problem
Traditional insulated plug systems for high voltage devices face issues with inconsistent torque application, leading to potential joint failure due to over- or under-torquing, as users often rely on standard wrenches without precise torque control, which is rare in utility trucks.
Innovation Solution
An insulated plug assembly featuring a torque limiting bolt system with a first hex element, a second removable hex element, and a shearable shaft element, allowing for precise torque application and ensuring secure attachment without damaging the joint, using a standard wrench.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a standard wrench is used to tighten the insulated plug, then ease of operation is improved, but torque precision deteriorates leading to potential joint failure
Solution Approach 1:
The torque limiting device performs the torque control function automatically without requiring external measurement tools. The shearable shaft element self-regulates the torque application by shearing at the predetermined torque value, eliminating the need for utility workers to carry or use torque wrenches.
Solution Approach 2:
The device changes the physical state of the shearable shaft element from intact to sheared at a specific torque parameter. This parameter-based failure mode provides precise torque control - the shaft is designed to shear at exactly the torque value needed to secure the plug without over-torquing.
2Strength
If torque is applied to secure the insulated plug, then connection strength is improved, but joint damage may occur due to over-torquing
Solution Approach 1:
The shearable shaft element is pre-designed with a specific shear strength that corresponds to the maximum safe torque for the joint. Before tightening occurs, the device is configured to automatically prevent torque exceeding this predetermined value, eliminating the risk of over-torquing damage.
Solution Approach 2:
The device converts the potentially harmful effect of excessive torque into a beneficial safety feature. The shearable shaft element is designed to fail in a controlled manner at the exact torque level needed, transforming what would be a damaging overload into a protective mechanism that prevents joint damage.
3Object-affected harmful factors
If torque is not applied sufficiently, then joint damage is prevented, but connection reliability deteriorates
Solution Approach 1:
The shearable shaft element is engineered with a specific shear strength parameter that corresponds to the minimum torque required for reliable connection. When this parameter is reached, the shaft shears, providing positive confirmation that adequate torque has been applied and the connection is reliable.
4Measurement precision
If a torque wrench is used, then torque precision is improved, but device complexity and availability deteriorate
Solution Approach 1:
The torque limiting device integrates the torque control function directly into the plug assembly, making it self-sufficient. The shearable shaft element automatically performs the torque measurement and limitation function that would otherwise require a separate torque wrench tool.
Solution Approach 2:
The torque control function is merged with the plug tightening function. The shearable shaft element combines the structural support function with the torque limitation function, eliminating the need for a separate torque wrench tool.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures proper torque is applied to secure the insulated plug into the joint elbow, preventing failure by shearing the shearable shaft element when adequate torque is reached, eliminating the need for a torque wrench and providing a secure, reliable connection.
Implementation Method 1
a shearable shaft element attached to the first hex element and the second hex element, where the shearable shaft element is configured to shear when a predetermined torque value is exceeded
Data Source
AI summary
An insulated plug for use in a high voltage device includes a torque limiting bolt, including a first hex element, a second hex element, and a shearable shaft element. Alternatively, an insulated plug assembly for use in a high voltage device includes an insulated plug having a torque limiting bolt, where the torque limiting bolt includes a first hex element attached to the insulated plug and a second hex element attached to the first bolt head via a shearable connector, the assembly further including a separate BIP cap.